American didn't provide more details about what systems and airlines were affected. Reports on Twitter indicated outages at American, Alaska Airlines and JetBlue; all three responded to several tweets about saying computers, kiosks or the website not working.

We are aware of the issues facing some of our customers. Recovery is in progress and will provide more information in real time.

American Air confirmed that the issue was with Sabre, and that it affected more than one airline.

"Earlier today, Sabre had a brief technical issue that impacted multiple carriers, including American. This technical issue has been resolved. We apologize to our customers for the inconvenience," the company said in a statement.